[untilcomplete]

It's usually use plastic boxes but couldn't really work it for this situation. Ended up using a metal box. Romex coming in from the ceiling. Box is grounded. Do I need to place a rubber grommet in the hole on the metal box? Thanks!
http://imgur.com/Kp4PBCv

 

[Jim Port]

No, you need to use a listed clamp for NM cable.

 

[untilcomplete]

No, you need to use a listed clamp for NM cable.

Ok thanks!